Aetna CEO: Obamacare In A 'Death Spiral' Heading Into 2018. Aetna and Humana have called off their deal amid government concerns over competition. Here's a look back at six pivotal moments that led to this. Aetna and Humana have called off their deal amid government concerns over competition.
For the plant genus, see Synapsis (plant). Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
Answers. Best Answer: The area that includes the presynaptic membrane, the synaptic cleft, and the postsynaptic membrane is called a synape. When the nerve impulse reaches the nerve endings it causes the presynaptic membrane to become more permeable to calcium.nswers. Best Answer: The area that includes the presynaptic membrane, the synaptic cleft, and the postsynaptic membrane is called a synape. When the nerve impulse reaches the nerve endings it causes the presynaptic membrane to become more permeable to calcium.